The Link Between Alcoholism and Eating Disorders

The comorbidity between alcoholism and eating disorders, especially in young women, is well documented. Alcohol and other drug (AOD)-use disorders are particularly common in women with bulimia nervosa. Although the mechanisms underlying the coexistence of these disorders remain unknown, recent family epidemiology studies suggest that bulimia nervosa and AOD dependence are transmitted independently in families. Furthermore, bulimia nervosa generally develops before the onset of AOD dependence. Thus, factors other than addictive behavior may contribute to the development of bulimia nervosa in a substantial proportion of women. The comorbidity of AOD-use disorders with eating disorders has implications for the treatment of the affected patients.


COMMON EATING DISORDERS
episodes are interspersed with recurrent alcoholic patients or patients compensatory purging behavior(s), with eating disorders have ob The two most common eating disor such as vomiting or laxative abuse, to ders are bulimia nervosa and anorexia prevent weight gain. In addition, the served that both types of disorders nervosa. Both disorders primarily af patients' selfevaluations are unduly frequently cooccur. Only recently, fect young women, with the usual ages influenced by their body shape and however, have researchers begun to of onset being between early and late weight (APA 1994). investigate the reasons for this comor adolescence for anorexia nervosa and Anorexia nervosa is characterized bidity. This article describes some between adolescence and early adult by the relentless pursuit of thinness, characteristics of the most common hood for bulimia nervosa. Only ap intense fears of becoming fat, and a eating disorders and reviews studies proximately 10 percent of all eating distorted body image. People with disorder cases occur in men. Because examining their comorbidity with al anorexia nervosa experience substantial of this gender distribution, the vast coholism and other druguse disorders. 1 weight loss. In female patients, the re majority of studies have investigated Moreover, the article presents the find sulting changes in the hormonal system eating disorders only in women. There ings of preliminary analyses of the also lead to the absence of menstruation fore, this review also focuses mainly (i.e., amenorrhea) (APA 1994). Accord mechanisms that might contribute to on studies of women with eating dis ing to the APA's Diagnostic and Sta the comorbidity of alcohol and other orders. Clinically diagnosable eating tistical Manual of Mental Disorders, drug (AOD)use disorders and eating disorders are relatively rare in the Fourth Edition (DSM-IV), two types disorders. Finally, the article reviews general population. The lifetime pre the implications of these findings for valence rates are 1 to 3 percent for bulimia nervosa and 0. (i.e., binge eating). These bingeeating Pittsburgh, Pennsylvania.
of anorexia nervosa exist: a restrict ing type and a bingeeating/purging type. Patients with restricting anorex ia nervosa lose weight primarily by extremely restricting their food intake. Patients with bingeeating/purging anorexia nervosa achieve or maintain a subnormal weight by regularly engaging in bingeeating and purging behavior in addition to restricting their food intake. Thus, bingeeating/ purging anorexia nervosa differs from bulimia nervosa in that the anorexic is severely underweight and amenorrheic, whereas the bulimic typically is of nor mal weight. These distinctions are important, because the rates of alcohol use disorders vary among women with different eating disorders. Another eating disorder described provisionally in the DSM-IV is binge eating disorder (APA 1994). Like bulimia nervosa, it is characterized by the recurrent consumption of large amounts of food in short periods of time and lack of control during these bingeeating episodes. In contrast to bulimia nervosa, however, compen satory purging behavior does not oc cur. Only very limited research has been conducted on the rates of alcohol use disorders among women with bingeeating disorder, and these studies have led to conflicting results (Spitzer et al. 1993;Wilson et al. 1993). There fore, this review focuses only on the association of AODuse disorders with bulimia nervosa and anorexia nervosa.
The causes and mechanisms (i.e., the etiology) underlying eating disor ders remain unknown but most likely include genetic and environmental factors. Twin studies suggest that for bulimia nervosa, approximately 50 percent of the risk is attributable to genetic factors and 50 percent is at tributable to the environment (Kendler et al. 1995). Moreover, the rates of eating disorders are elevated among the relatives of eatingdisordered women (Lancelot et al. 1991), sug gesting a familial etiology that may include both genetic and environ mental effects.

RATES OF AODUSE DISORDERS AMONG WOMEN WITH EATING DISORDERS
Numerous studies have investigated the prevalence of AODuse disorders among women with eating disorders. A recent review of 51 studies (Holder ness et al. 1994) suggests that the rates of AODuse disorders differ signifi cantly among restricting anorexics, bingeeating/purging anorexics, and bulimics. Depending on the study analyzed, the rates of alcohol abuse or dependence among restricting anorexics ranged from 0 to 6 percent and the rates of other drug abuse or dependence (including amphetamines) ranged from 5 to 19 percent. In contrast, the corre sponding rates in bulimics were signif icantly higher, ranging from 14 to 49 percent for alcohol abuse or dependence and from 8 to 36 percent for other drug abuse or dependence. Comparably high rates of alcoholuse disorders also were found in bingeeating/purging anorexics (see Laessle et al. 1989).
A recent survey of AODuse disor ders among women in the general pop ulation showed rates of 12 percent for alcohol abuse or dependence and 10 percent for other drug abuse or depen dence (Kessler et al. 1994). Therefore, compared with women in the general population, women with bulimia ner vosa or bingeeating/purging anorexia nervosa appear to have elevated rates of AODuse disorders, whereas restricting anorexic women have lower rates of alcoholuse disorders but similar rates of other druguse disorders. The rela tively high rates of druguse disorders, even among restricting anorexics, likely are attributable to the abuse of ampheta mines and other drugs as a means of weight loss.
Women with different eating disor ders also differ in their rates of regular alcohol use (i.e., not abuse or depen dence): These rates were substantially higher among bulimics and binge eating/purging anorexics (45 percent) than among restricting anorexics (11 percent) (Bulik et al. 1992). These variations could not be accounted for by age differences across groups. In addition, the rates of caffeine, laxa tive, and cigarette use were higher among bulimics and bingeeating/ purging anorexics than among re stricting anorexics. Thus, bulimics and anorexics with bulimic symptoms are more likely to use and abuse AOD's than are restricting anorexics.

RATES OF EATING DISORDERS AMONG ALCOHOLIC WOMEN
The frequency of eating disorders among alcoholic women has been studied less extensively than the fre quency of alcoholuse disorders among eatingdisordered women. Several studies have found, however, that the lifetime rates of any comorbid eating disorder among AODabusing women are significantly higher than in the gen eral population, ranging from 15 to 32 percent (Higuchi et al. 1993;Beary et al. 1986;Hudson et al. 1992). With respect to specific eating disorders, both bu limia nervosa and bingeeating/purging anorexia nervosa are more common than restricting anorexia nervosa in both alcoholic populations (Higuchi et al. 1993;Beary et al. 1986) and mixed AODabusing populations (Hudson et al. 1992). According to these analyses, the rates of bulimia nervosa and binge eating/purging anorexia nervosa range from 12 to 20 percent, whereas the rates of restricting anorexia nervosa range from 2 to 10 percent.
One study of eating disorders among female and male Japanese alco holics (i.e., people with a diagnosis of alcohol abuse or dependence) in inpa tient treatment found that 11 percent of the female alcoholics and 0.2 percent of the male alcoholics had lifetime histories of eating disorders (Higuchi et al. 1993). The very low rates of eating disorders among the male pa tients were consistent with lifetime prevalence rates of 0.01 to 0.1 percent for anorexia nervosa and 0.1 to 0.3 per cent for bulimia nervosa observed among males in the general popula tion. Thus, in contrast to female alco holics, male alcoholics do not appear to experience significantly elevated rates of eating disorders compared with the general population.
A striking finding emerged when the researchers analyzed different age groups of female alcoholics: Seventy two percent of all the female alcoholics under the age of 30 had lifetime his tories of comorbid eating disorders, compared with 11 percent in the entire sample. Again, the majority of these patients (89 percent) suffered from either bulimia nervosa or bingeeating/ purging anorexia nervosa. Thus, the association between eating disorders with bulimic features and alcoholuse disorders appears to be particularly strong among young women. The rea sons for this concentration of eating disorders among young women are unclear. Although bulimia nervosa has been defined only relatively recently (Russell 1979), its rates do not seem to be increasing (Frombonne 1996). Therefore, the age specificity most likely is not attributable to a cohort ef fect. Given the usual age of onset, how ever, younger women are more likely than older women to have current or recent histories of bulimia nervosa and therefore may be more reliable reporters of such histories.
Another study that examined the rates of eating disorders among female alcoholdependent inpatients found that 30 percent of these women had lifetime histories of eating disorders (Beary et al. 1986). Onethird of these women were diagnosed with anorexia nervosa, and twothirds were diagnosed with bulimia nervosa. In both studies (Higu chi et al. 1993;Beary et al. 1986), the eating disorder preceded the onset of the alcoholuse disorder in the majority of cases.
In summary, the literature on both eating disorders and AODuse disorders supports clinical observations of the frequent cooccurrence of both types of disorders. Furthermore, bulimia nervosa and the bulimic (i.e., binge eating/purging) subtype of anorexia nervosa are much more commonly associated with alcoholuse disorders than restricting anorexia nervosa. These findings are consistent with past re search that determined behavioral and personality trait differences among pa tients with different eating disorders. For example, bingeeating/purging anorexics and bulimics share certain traits characteristic of impulsive behav ior and mood swings, whereas restrict ing anorexics consistently have been described as behaviorally restrained and compulsive (Vitousek and Manke 1994). Based on these characteristics, it is not surprising that bulimics and bingeeating/purging anorexics have high rates of AODuse problems, whereas restricting anorexics do not exhibit AODuse problems or other impulsive behaviors.

PATTERNS OF AODUSE AND EATING DISORDERS IN FAMILIES
Although studies have confirmed that eating disorders and AODuse disorders frequently coexist, the mechanisms un derlying this comorbidity have not been elucidated. At least four potential expla nations exist for the high rates of co morbidity (Klein and Riso 1993): • Both disorders are different mani festations of a shared underlying etiology.
• The two disorders have different causes, but the presence of one disorder may increase a person's chances of developing the other.
• An independent disorder causes both disorders.
• The two disorders have some risk factors in common, whereas other risk factors are specific to each disorder.
The first hypothesis of a common etiology has been studied most exten sively. Supporters of this hypothesis believe that both eating disorders and AODuse disorders may be manifesta tions of an underlying predisposition toward impulsivity or may result from a common mechanism involving en dogenous opioids (Wilson 1991). En dogenous opioids-compounds that occur naturally in the body and act like opiates-have been shown to play a role in regulating alcohol consumption as well as appetite (Swift 1995;Jackson et al. 1992). One way to investigate this hypothesis is to use a family study design, in which the prevalence of a disorder (e.g., alcoholism) is compared between the relatives of a particular pa tient population (e.g., patients with eat ing disorders) and the relatives of the normal control subjects. Family studies are a wellaccepted approach to study ing the mechanisms underlying the fre quent coexistence of two disorders (see Merikangas et al. 1994).
Very few studies have investigated the possible roles of transmissible ge netic or environmental familial factors in the comorbidity of eating disorders and alcoholuse disorders. In a recent family study, Kaye and colleagues (in press) assessed the presence of psychi atric disorders, including AODuse disorders, among restricting anorexics, bulimics, and noneatingdisordered women and their firstdegree relatives using direct structured interviews. One question addressed by this study was whether bulimia nervosa and AOD use disorders represent alternative ob servable manifestations (i.e., phenotypic expressions) of a shared transmissible factor. If so, family members of bulim ics should exhibit elevated lifetime rates of AOD dependence, regardless of the presence or absence of AOD de pendence in the bulimics themselves. Alternatively, bulimia nervosa and AOD dependence could be coexisting but separate disorders (Merikangas et al. 1994). In that case, only relatives of bulimic subjects with coexisting AOD dependence would have a higher prev alence of AOD dependence, where as the relatives of bulimic subjects without coexisting AOD dependence would have AOD dependence rates similar to those among relatives of nonbulimic women.
Accordingly, the researchers divided the bulimic subjects into two groups: those with and those without lifetime histories of comorbid AOD dependence. When the rates of AOD dependence were examined in the firstdegree rel atives of both groups, the prevalence was elevated only among the relatives of bulimics with comorbid AOD de pendence but not among the relatives of nonAODdependent bulimics. The analyses produced similar, though less robust, results when the rates of not only AOD dependence but also AOD abuse and dependence were evaluated. These findings refute the hypothesis that eat ing disorders and AODuse disorders are different manifestations of a shared underlying etiology and indicate instead that both disorders are attributable to independent transmissible factors.
If many bulimic women do not ex hibit familial vulnerability to AODuse problems, factors other than addictions may contribute to the development of bulimia nervosa in a substantial pro portion of women. These findings raise the possibility that two bulimic sub types exist. The first type would repre sent a "multiimpulsive" subtype, with a familial and personal history of AOD use problems. The second type may best be described as an "anorexiclike" subtype, with personality and behav ioral traits similar to restricting anorex ics (e.g., behavioral restraint and compulsiveness). Similar to restricting anorexics, these bulimics have no ex tensive personal or family histories of AODuse problems.
Other recently published studies also suggest that alcoholism and bulimia ner vosa do not share a common etiology. For example, Schuckit and colleagues (1996) conducted structured interviews with 2,283 women and 1,982 men as part of the Collaborative Study on the Genetics of Alcoholism. The sample consisted of women and men who were alcohol dependent 2 as well as their first and seconddegree relatives. The sub jects included both "primary alcoholics," whose onset of alcohol dependence preceded the onset of any other psy chiatric disorder, and "secondary alco holics," whose onset of alcohol dependence followed the onset of one or more comorbid disorders. The study did not detect significantly higher rates of eating disorders among the relatives 2 Alcohol dependence in this study was defined according to the criteria of the American Psy chiatric Association's Diagnostic and Sta tistical Manual of Mental Disorders, Third Edition, Revised. of primary alcoholics or among the relatives of primary and secondary alcoholics combined than among the relatives of nonalcoholic comparison subjects. The authors concluded that "any relationship that might exist between anorexia nervosa or bulimia nervosa, on the one hand, and alcohol dependence, on the other, is not likely to represent a strong genetic linkage with alcohol dependence itself" (Schuckit et al. 1996, p. 80).
Genetic analyses of six major psy chiatric disorders in women, including bulimia nervosa and alcoholism, sup ported the existence of separate genetic liabilities for eating disorders and al coholism (Kendler et al. 1995). The study included 1,030 female twin pairs, ascertained from the general population through the Virginia Twin Registry, who were evaluated through direct interviews. Statistical analyses exam The rates of alcoholuse disorders vary among women with different eating disorders.
ining correlations of multiple vari ables between and across twin pairs indicated that bulimia nervosa and alcoholism were best explained by two different genetic factors. In fact, most genetic factors that influenced the women's vulnerability to alco holism appeared to be distinct from the genetic factors determining the risks for other disorders, including bulimia nervosa.
Thus, the three epidemiological studies described here suggest that al though bulimia nervosa and alcohol ism frequently coexist, they apparently do not share an underlying familial or genetic liability. Instead, the two dis orders are likely to result from inde pendent causal factors.
The other three potential explana tions for the high rates of comorbidity between alcoholism and eating disor ders have been examined less thor oughly. Most studies investigating the hypothesis that the presence of one disorder may increase the chances of developing the other disorder found that the onset of bulimia nervosa gen erally preceded the onset of alcohol dependence (see Higuchi et al. 1993). Although this observation is not sur prising, given the different ages of on set for the two disorders, it does not resolve the question of whether this temporal pattern also indicates that bulimia nervosa somehow causes the onset of alcohol dependence.
The theory that an independent disorder can cause both eating disor ders and alcoholism also has not been well studied. One potentially fruitful line of research would be to examine the relationship among anxiety disor ders, bulimia nervosa, and alcoholism, because anxiety disorders frequently cooccur with both of the other disor ders (Brewerton et al. 1995;Brady and Lydiard 1993).
The most likely-although also not wellinvestigated-explanation of the frequent comorbidity of eating disor ders, particularly bulimia nervosa, and AODuse disorders may be that people with both types of disorders share some underlying traits, such as periodic behavior disinhibition and difficulty modulating feelings or emotions (i.e., affect). In addition to these shared traits, other etiologic factors likely exist that are specific to each disorder. Clearly, more research is needed to further evaluate this hypothesis.

TREATMENT IMPLICATIONS
Over the past decade, several re searchers have hypothesized that bu limia nervosa, like alcoholism, is a type of addictive disorder (Vandereycken 1990;Wilson 1991). Both alcoholics and bulimics describe feelings of "craving" and a "loss of control" over a substance (i.e., alcohol or food), become preoccupied with the sub stance, and repeatedly attempt to stop their pattern of overconsumption. More over, both disorders can impair a per son's physical and social functioning and may involve deception and secrecy.
The addiction model of eating dis orders (Wilson 1991) has contributed to the notion that eating disorders and AODuse disorders may respond to similar treatment approaches. In fact, many bulimics are treated in 12step like programs, and Johnson and San sone (1993) describe a program in which more traditional therapy mo dalities are combined with a 12step component. To date, however, no rigor ous, scientifically designed studies have demonstrated the benefits of a 12step approach for treating bulimia nervosa. Moreover, because the 3 re cent epidemiological studies have de monstrated that bulimia nervosa and AODuse disorders have independent liabilities, it is possible that 12step like programs may not be useful for bulimics without coexisting AOD use problems.
In contrast, other therapies, such as cognitivebehavioral therapy (CBT) and antidepressant medication, have proven useful in treating eating disor ders (Abbott and Mitchell 1993). CBT focuses on identifying and restructur ing distorted thoughts (e.g., a negative body image and fears of fatness), which in turn influence behavior. Other, more specific behavioral strategies used in treating eating disorders may include imposing a timedelay between a binge episode and the vomiting episode that usually immediately follows binge eat ing, with the goal to gradually increase the time delay.
The most effective treatment ap proaches for alcoholism and eating dis orders also will likely differ, because different behaviors must be addressed for both types of disorders. The pri mary focus in alcoholism treatment is to avoid consuming the substance, whereas the focus in bulimia nervosa treatment is to change the manner in which the substance (i.e., food) is con sumed. Many bulimics and binge eating/purging anorexics have difficulty modulating food intake and often alter nate between periods of imposed food restriction and overconsumption com bined with purging behaviors. Treat ment must take into consideration both these consumption patterns as well as a disturbed body image. Accordingly, cognitivebehavioral approaches ad dressing all these issues differ greatly from the 12step programs commonly used to treat alcoholics.
Few empirical data exist to help identify and treat patients with coex isting eating disorders and AODuse disorders. Still, the frequent comor bidity of these disorders underscores the necessity of determining whether eating disorders are present, especially among young, AODabusing women entering treatment. Adequate assess ment is even more important, because alcoholic, eatingdisordered patients also are likely to engage in other behav iors common among "multiimpulsive bulimics," such as shoplifting, suicide attempts, or selfmutilating behavior (Suzuki et al. 1994). These character istics may have significant implica tions for the clinical management of such patients.
AODabusing patients with coex isting eating disorders should receive thorough medical assessments and nutritional consultations. The manage ment of these patients should include monitoring their weight, food intake, and purging behavior as well as as sessing their cardiac, fluid, and min eral (i.e., electrolyte) statuses. The patients should be observed during and after each meal, with supervised bathroom use to minimize purging opportunities. Although monitoring eatingdisordered patients in an AOD abuse treatment facility may be chal lenging and labor intensive, it is necessary for treatment.
Patients with comorbid AODuse and eating disorders can pose a particu lar challenge for the individual clinician or the staff of a treatment facility. These patients may represent a group distinct from patients who only have an AOD use disorder or an eating disorder. They may require different, more varied, and more intensive assessment and treat ment approaches. Researchers and clinicians still have not identified the most beneficial treatment approaches for these patients, and future treatment outcome studies must address this dif ficult patient population. ■ Women and Alcohol: Issues for Prevention Research,No. 32, presents current research conducted by noted scientists in the area of alcohol use among women and provides recommendations for future studies that could better serve this population. Topics include alcohol use across the life span; alcohol use in the workplace; alcoholrelated birth defects; drinking and driving; parenting interventions for preventing alcohol and other drug use among children; and the role and/or influence of genetics, sexuality, and violent victimization on alcohol use.
Alcohol and the Cardiovascular System, No. 31, examines research pertaining to the consequences of both moderate and heavy alcohol consumption on the heart, blood, and blood vessels. This monograph is divided into four major sections: Epidemiological Studies, Clinical Studies, Biochemical and Molecular Studies, and Alcohol Interactions With Other Medications.